Cannabis has reportedly provided users with relief from a variety of medical ailments including chronic pain, epilepsy, inflammation, and nausea resulting from chemotherapy. See, for example, Laura M. Borgelt et al., The Pharmacologic and Clinical Effects of Medical Cannabis, Pharmacotherapy (2013) 33(2):195-209; Penny F. Whiting et al. Cannabinoids for Medical Use: A Systematic Review and Meta-Analysis, JAMA (2015) 313(24):2456-2473, doi:10.1001/jama.2015.6358; Bjorn Jensen et al., Medical Marijuana and Chronic Pain: A Review of Basic Science and Clinical Evidence, Curr. Pain Headache Rep. (2015) 19:50, https://doi.org/10.1007/s11916-015-0524-x; and Guillermo Velasco et al., Towards the Use of Cannabinoids as Antitumour Agents, Nature Reviews Cancer 12 (2012) 436-444, doi:10.1038/nrc3247, which are hereby incorporated by reference.
To achieve such relief, users have often consumed liquid cannabis extracts as an alternative to smoking cannabis plant material. Current methods have been able to create cannabis extracts from raw cannabis plant material, and have produced concentrated amounts of biologically active compounds, i.e., cannabinoids, terpenes, terpenoids, and flavonoids, or more specifically, tetrahydrocannabinol (THC), cannabidiol (CBD), cannabinol (CBN), cannabichromene (CBG), tetrahydrocannabivarin (THCV), and others. For example, existing methods of extraction have produced cannabis extracts consisting of ninety percent (90%) or greater THC, whereas a cannabis plant from which the extract was derived has only consisted of fifteen percent (15%) or less THC. The resulting cannabis extracts have been more potent by volume than the raw botanical material from which they were derived, and thus users have reportedly experienced comparable effects, or even greater effects, though they have consumed far smaller volumes of cannabis extract than would have otherwise been required to achieve those effects.
Prior art methods for preparing food grade cannabis extracts have involved using solvents such as supercritical—or subcritical—carbon dioxide (CO2), butane (C4H10), liquid propane (C3H8), and ethanol (C2H6O). These solvents have often been used to produce cannabis extracts with maximum potency, e.g., they have produced higher concentrations of THC, CBD, or other chemical compounds found in cannabis. However, the prior art methods by themselves have reportedly done little or nothing to reduce or eliminate an undesirable side effect of creating or exacerbating anxiety in a user. Increased anxiety has generally been considered to be an adverse reaction to elevated levels of THC, and this may especially have been a problem for users already having suffered from stress or anxiety. Although not all users have experienced increased anxiety as a result of having consumed cannabis, this undesirable effect has prevented many individuals suffering from medical ailments from being able to comfortably consume cannabis products, and has deterred individuals from consuming cannabis products altogether.
Responsive to the limitations of the prior art, recent trends in the cannabis industry have included preparing cannabis extracts from cannabis strains that have been rich or dominant in CBD, and that have had little to no THC content. The benefit of having prepared extracts from CBD-rich or CBD-dominant strains is that CBD may have counteracted the anxiety effect caused by THC, and consequently may have provided users with relief from certain medical conditions without having created or having exacerbated anxiety. However, cannabis extracts having lower levels of THC may also have been less medically effective than their THC-rich counterparts. For example, scientists have noted that THC has been medically useful because it has had the greatest anti-cancer activity of all cannabis compounds. In either case—whether with cannabis extracts having higher levels of THC that may have induced or increased anxiety in a user, or with cannabis extracts that have had lower levels of THC that has rendered them less medically valuable—the outcome has been that a user may not have experienced optimal or desired results.
Accordingly, there has developed a need for cannabis extracts, and methods for their preparation, that would reduce or eliminate the anxiety effect on a user without requiring the extracts to have a lower THC content.